1. Field of the Invention
The present invention relates to a silver halide photographic light-sensitive element containing a novel oxonol dye.
2. Description of the Prior Art
In silver halide photographic light-sensitive elements, photographic emulsion layers and other layers are often colored in order to absorb light in a particular wavelength region.
Where the spectral composition of the light incident upon a photographic emulsion layer or layers must be controlled, a colored layer may be positioned in a position more remote from the support than the photographic emulsion layer or layers. Such a colored layer is referred to as a filter layer. In photographic elements containing a plurality of photographic emulsion layers such as multilayer color light-sensitive elements, a filter layer may be positioned between two emulsion layers.
A colored layer may also be positioned between the support and the photographic emulsion layer, or on the side of the support opposite to that on which the emulsion is coated in order to prevent blurring of the image, i.e., halation, caused by re-entry into an emulsion layer of light that is scattered during or after transmission through the emulsion layer and reflected at the interface between the emulsion layer and the support. Such a colored layer is referred to as an antihalation layer. In photographic elements containing a plurality of photographic emulsion layers such as multilayer color light-sensitive elements, an antihalation layer may be positioned between two emulsion layers.
Dyeing of one or more photographic emulsion layers is also employed in order to prevent a reduction of the sharpness of the image due to the scattering of light in photographic emulsion layers. (This phenomenon is generally referred to as irradiation.)
Most of these colored layers comprise a hydrophilic colloid, and accordingly water-soluble dyes are usually incorporated thereinto to dye the layers. Dyes to be used for this purpose must have an appropriate spectral absorption property and, in addition, have to satisfy the following requirements:
(1) They should be photographically inert. That is, they should not chemically adversely affect the layers, such as reduce the sensitivity, fade the latent image and generate fog.
(2) They should remain in the dyed layer until the element is subjected to photographic processing. That is, they should have a good mordanting property. (3) They should be decolorized or removed by dissolving during photographic processing, leaving no harmful stain on the photographic light-sensitive element after the processing. That is, they should have a good bleachability.
Of the above requirements, the mordanting property (2) is the most important. Because, if the dye does not remain in the dyed layer, it may reduce the sensitivity of other photographic emulsion layers and cause a color imbalance among blue, green and red, which is undesirable for the reproduction of color.
Much effort has been made to find dyes which satisfy these requirements. Examples of known dyes include oxonol dyes containing a pyrazolone nucleus, such as those described in British Patent No. 506,385, Japanese Patent Publication Nos. 22,069/64 and 13,168/68, and Japanese Patent Application (OPI) No. 85,130/73; oxonol dyes containing a barbituric acid nucleus, such as those described in U.S. Pat. Nos. 3,247,127 and 3,653,905; other oxonol dyes as described in U.S. Pat. No. 2,533,472, British Patent No. 1,278,621 and French Patent No. 1,401,588; benzilidene- (or cinnamylidene)pyrazolone dyes, such as those described in British Patent No. 584,609, U.S. Pat. Nos. 3,540,887, 3,615,546 and 3,687,670, and French Patent Nos. 1,350,311 and 1,421,679; and merocyanine dyes, such as those described in British Patent Nos. 1,075,653 (the one represented by general formula (IV)), 1,153,341 and 1,284,730, and French Patent No. 1,401,588 (the ones represented by general formula (II)).
However, no dye is known which simultaneously satisfies the above three requirements. In particular, most of the known dyes do not have satisfactory mordanting properties. Oxonol dyes containing barbituric acid nuclei as described in U.S. Pat. Nos. 3,247,127 and 3,653,905 can not be said to be satisfactory in both mordanting and decolorizing properties.